This invention relates to pulse detonation systems, and more particularly, to an inlet airflow management system for use on a pulse detonation engine for supersonic applications.
With the recent development of pulse detonation combustors (PDCs) and engines (PDEs), various efforts have been underway to use PDC/Es in practical applications, such as combustors for aircraft engines. Just as with any normal air breathing engine, inlet stability is an important aspect of maintaining proper operation of a pulse detonation engine. This is particularly true in applications with multiple combustors with a common inlet, where it is important to minimize or eliminate disruptions to the inlet. Such disruptions include pressure fluctuations, which have the potential to “un-start” or stall the airflow through the inlet, compressor, or other upstream devices.
These problems are particularly prevalent in pulse detonation engines which use open inlet tubes. During operation, PDE's create a high pressure detonation wave used for propulsion (as it exits the PDE). However, it has also been observed that a forward propagating pressure wave, which may contain fuel-air reaction products, is generated. Because the pulse detonation process is a high pressure rise process, these forward propagating pressure waves may provide enough perturbation to “un-start” the PDE inlet, as well as expose some of the upstream components to high pressure pulses, which could cause damage to these components.
Thus, it is desirable to provide some means or methodology to block these forward propagating pressure waves. Some efforts have been made to accomplish this by using conventional air flow valves. However, because of the operational pressures and frequencies involved (which can be as high as 100 Hz), such devices have had limited or no success.
Therefore, there exists a need to block any upstream pressure waves generated by a detonation, using a relatively simple and robust system. It is noted that although the expression “pulse detonation engine” is used herein, this term is intended to describe all combustion type devices employing pulse detonation technology, including but not limited to pulse detonation combustors, and the like.